Big Green: White TPO vs EPDM and paint

[Dean Sherwin]

At 10:51 AM 5/5/2008, Green Hornet wrote:
>I have long recommended ballasted loose-laid TPO for single-ply 
>membrane.... for reflectance use white quartzite gravel with a 
>protection board layer.

Good to see someone still recommends ballasted roofing.  It was all 
the rage in '70's/ early '80's, then pretty much vanished at least in 
my region (MidAtlantic)  Of course it has drawbacks, don't we 
all.   But as far as I can see it does most of what is claimed for 
green vegetated roofs, for far less cost. It will not mitigate 
stormwater, for those congested sites where that is important.  But 
as for: "cool" reflective roof, protect the membrane, thermal mass 
outside the insulation - yep yep and yep.  It certainly is not a 
visual amenity in the same way, so for a highly visible green roof, 
it's the aesthetic amenity that the vegetation part scores on.  And 
that is no meaningless amenity for sure.
Dean Sherwin